CN1784107A - 在大面板应用中驱动放电灯的方法和保护设备 - Google Patents
在大面板应用中驱动放电灯的方法和保护设备 Download PDFInfo
- Publication number
- CN1784107A CN1784107A CNA2005101134644A CN200510113464A CN1784107A CN 1784107 A CN1784107 A CN 1784107A CN A2005101134644 A CNA2005101134644 A CN A2005101134644A CN 200510113464 A CN200510113464 A CN 200510113464A CN 1784107 A CN1784107 A CN 1784107A
- Authority
- CN
- China
- Prior art keywords
- current
- feedback voltage
- safe
- equipment
- transformer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
- H05B41/14—Circuit arrangements
- H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
- H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
- H05B41/288—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices and specially adapted for lamps without preheating electrodes, e.g. for high-intensity discharge lamps, high-pressure mercury or sodium lamps or low-pressure sodium lamps
- H05B41/292—Arrangements for protecting lamps or circuits against abnormal operating conditions
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
- H05B41/14—Circuit arrangements
- H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
- H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
- H05B41/282—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices
- H05B41/2825—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices by means of a bridge converter in the final stage
- H05B41/2828—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices by means of a bridge converter in the final stage using control circuits for the switching elements
Landscapes
- Circuit Arrangements For Discharge Lamps (AREA)
- Inverter Devices (AREA)
Abstract
本发明提出了一种用于将直流电源切换为交流电源的简单的方法和设备,用以驱动放电灯例如驱动冷阴极荧光灯(CCFL)、外部电极荧光灯(EEFL)或平板型荧光灯(FFL)。该方法包括:监测所述变压器负载侧的反馈电压;如果所述反馈电压高于预设阈值,则使正常工作继续;以及如果所述反馈电压低于预设阈值,则将所述驱动设备提供的电流限制为安全电流ISAFE。在其它优点中,在正常灯电流高于安全电流极限的情况时的应用中,本发明能在短路情况下进行适当保护。
Description
本发明基于2004年10月13日提交的美国临时专利申请号No.60/618,640要求优先权。
技术领域
本发明涉及荧光灯的驱动技术,特别涉及驱动冷阴极荧光灯(CCFL)、外部电极荧光灯(EEFL)以及平板型荧光灯(FFL)的方法和保护设备(scheme)。
背景技术
在大面板显示器(例如LCD电视)中,使用许多并联的灯以提供高质量画面所需的亮背光。全亮度时的总电流会轻易超过由政府规章所确定的电流极限。例如,如保险商实验室(UL)标准UL60950中所述的,在功率变换器短路2000欧姆阻抗时,电流极限不能超过70mA。但是,在一般的有20个灯的背光灯设备中的二次侧电流可能会超过该电流量。
传统保护设备通常测量灯电流、变压器初级电流或变压器电流。然后,将这些电流限制得低于最大的安全电流。但是,这种方法仍有缺点。
发明内容
本发明的目的是提供一种驱动设备中短路保护的方法,该驱动设备经由变压器来驱动灯负载,该方法包括:监测所述变压器负载侧的反馈电压;如果所述反馈电压高于预设阈值,则使正常工作继续;以及如果所述反馈电压低于预设阈值,则将所述驱动设备提供的电流限制为安全电流ISAFE。
其中,从串联的两个电容之间的节点监测所述反馈电压,所述两个电容与所述负载、所述变压器的二次侧并联。
其中,如果所述反馈电压在至少一个周期内低于所述预设阈值,则将所提供的电流限制为ISAFE。
其中,ISAFE是正常工作电流极限的均方根(root mean square),或者是所述正常工作电流的平均整流值。
其中,所述预设阈值在正常工作电压的25%到50%之间。
其中,所述正常工作包括亮度电流命令,该亮度电流命令为电流的上限。
本发明还提供一种驱动设备中短路保护的方法,该驱动设备经由变压器来驱动灯负载,该方法包括:监测所述变压器负载侧的反馈电压;确定所述反馈电压的均方根;将所述驱动设备提供的电流限制为亮度电流极限和所述反馈电压的均方根除以阈值阻抗RTH后的值的较小值。
本发明还提供一种经由变压器驱动灯负载的设备,包括:用于监测所述变压器负载侧的反馈电压的装置;用于确定所述反馈电压是否高于预设阈值的比较装置,并且(1)如果高于,则使正常工作继续;以及(2)如果不高于,则将所述设备提供的电流限制为安全电流ISAFE。
附图说明
图1是表示本发明的第一实施例的示意图;
图2是表示本发明的第二实施例的示意图;
图3是表示本发明的第三实施例的示意图;
图4是表示根据本发明在反馈节点上电流与电压关系的曲线图。
具体实施方式
本发明涉及一种在大面板应用中驱动放电灯的具有过电流保护功能的设备和方法。在其它优点中,本发明能提供接近对称的电压波形来驱动放电灯,能提供对灯电流的精确控制来确保良好的可靠性,还能提供在短路情况下限制电路电流的保护设备。
图1示出了本发明的一个实施例的简化原理图。通常,与CCFL设备相比,由于EEFL和FFL设备使用外部电极,因此,它们的阻抗更高。固有电容使串联阻抗显著增加。灯的阻抗一般在120K欧姆与800K欧姆之间。即使将30个灯并联,其总阻抗仍大于4K欧姆。如UL60950中所规定的,在2K欧姆时,测试短路阻抗。因此,本发明使用阻抗作为区别短路情况和正常工作情况的一种方式。下面描述本发明的几个实施例。
参考图1,全桥逆变电路101经由变压器105驱动灯负载103。灯负载103作为单个元件示出,但在有些实施例中也可表示多个CCFL、EEFL和/或FFL。图1还示出了控制&门驱动电路107,其执行两个主要功能:(1)提供适当的控制信号给全桥逆变电路101的晶体管,以及(2)接收反馈以监测各种参数。
图1的电路监测变压器二次侧电压的交流幅度作为一个参数,用以确定是否启动保护协议。电容C1、C2、C3、变压器的漏电感以及变压器的磁化电感(如果足够小)形成滤波电路,该滤波电路能将由全桥逆变器开关(Q1-Q4)所产生的方波电压切换为输入灯负载103的实质上的正弦波。
如上所述,控制&门驱动电路107产生具有适当占空比的门驱动波形,以将灯电流调整到参考电流极限。控制部分107还接收灯电流(在变压器105的二次侧的电流)的反馈。在感测变压器电压或灯电压时,电容C2和C3也用作分压器。电阻R1一般是较大的电阻,其能将零直流偏压加在电压反馈节点上。
应该注意到,如果在二次侧(或负载侧)的节点VL上的变压器电压(交流正弦波)的峰值没有超过预设阈值VTH(例如,节点VL上正常工作电压的40%),这表示可能出现短路情况。在可能出现短路情况时,将安全电流阈值ISAFE作为电流极限。例如,预设阈值VTH也可以设置为在正常工作电压的25%到55%之间。
在一个实施例中,ISAFE是正常工作电流的RMS值(均方根值)IRMS或者是平均整流值IRECT,AVG(IRECT,AVG=IRMS*2*sqrt(2)/π)。因此,可用多个电路实现的欠压检测单元(例如比较器)109用于将节点VL上的电压与VTH比较。如果VL在至少一个切换周期内比VTH低,欠压检测单元109将向电流极限选择单元111指示出短路情况,然后选择安全电流ISAFE作为电流极限。另外,欠压检测单元109将指示电流极限选择单元111选择“正常”电流极限,在一个实施例中所述“正常”电流极限由外部亮度命令等级(externalbrightness command level)IBRT来决定。但应理解的是,在有些实施例中,正常电流极限不限于IBRT,也可以是由其它可控参数设定的值。
应该注意到,如果变压器电压的负交流幅度没有降低到低于预设阈值VTH(例如,正常工作电压的40%),优选地,短路保护电流RMS值IRMS或平均整流值IRECT小于安全电流ISAFE。
图2中示出了图1的一个改型实施例。在图2中,电阻R2使VL偏压到VTH。因此,如果输入到欠压检测器109的电压在至少一个切换周期内没有降到低于零伏特,则VL的交流幅度小于VTH,即显示短路情况。
在UL60950中,2K欧姆的标准短路阻抗比CCFL、EEFL或FFL的灯阻抗小的多。因此,在灯应用中的二次电流或灯电流将比流经2K欧姆负载(用于UL60950测试)的电流小。
图3示出了本发明的另一个实施例。在该实施例中,当RTH/(1+C3/C2)在2K欧姆与最小灯阻抗之间的情况时设置RTH。如下所述,通过将RTH/(1+C3/C2)选择为大于2K欧姆,可以保证短路电流低于安全电流。如图3所示,RMS变换器301首先将反馈的灯电压VL转换成RMS值,然后输出表示为VLRMS的信号。与图2类似,R2用于消除反馈电压VL中的直流偏压。应该注意到,R2的值将被选择为明显高于灯的阻抗。接着,短路分析器303用于输出电流极限,该电流极限为VL/RTH和IBRT中的较小值。作为结果的电流极限在图4中示出。粗线表示正常工作电流。阴影区域表示在VL可能小于ISAFE*RTH的情况下LCC(限制电路的电流)保护区域。
只要(1+C3/C2)*VTH/IRMS>=1.4*2Kohm,就能保证该电路的短路电流始终比安全电流小,并能保证逆变器在较大灯电流(比安全电流大)下正常工作。
还应该注意到,短路电流在固频逆变器中可由单个电阻或电容测量,以及在变频逆变器中可由电阻和电容的并联组合测量。
前述的多个实例使用接地感测(grounded sense)来感测二次侧的电压。在其它实施例中,可在初级侧感测电压和/或电流。或者,可以使用用于漂移驱动逆变器的差分感测方案。而且,本发明所教导的内容还可以使用其它逆变器拓扑,包括推挽式、半桥式等。
如前所述,应理解的是:在此描述的本发明的特定实施例只是用于举例说明的目的,在不脱离本发明的精神和范围的情况下,可以对本发明进行各种修改。因此,本发明不受限于所附权利要求书的范围。
Claims (14)
1.一种驱动设备中短路保护的方法,该驱动设备经由变压器来驱动灯负载,该方法包括:
监测所述变压器负载侧的反馈电压;
如果所述反馈电压高于预设阈值,则使正常工作继续;以及
如果所述反馈电压低于预设阈值,则将所述驱动设备提供的电流限制为安全电流ISAFE。
2.如权利要求1所述的方法,其中从串联的两个电容之间的节点监测所述反馈电压,所述串联的两个电容与所述负载、所述变压器的二次侧并联。
3.如权利要求1所述的方法,其中如果所述反馈电压在至少一个周期内低于所述预设阈值,则将所述提供的电流限制为ISAFE。
4.如权利要求1所述的方法,其中ISAFE是正常工作电流极限的均方根,或者是所述正常工作电流的平均整流值。
5.如权利要求1所述的方法,其中所述预设阈值在正常工作电压的25%到50%之间。
6.如权利要求1所述的方法,其中所述正常工作包括亮度电流命令,该亮度电流命令为电流的上限。
7.一种驱动设备中短路保护的方法,该驱动设备经由变压器来驱动灯负载,该方法包括:
监测所述变压器负载侧的反馈电压;
确定所述反馈电压的均方根;
将所述驱动设备提供的电流限制为亮度电流极限与所述反馈电压的均方根除以阈值阻抗RTH后的值中的较小值。
8.如权利要求7所述的方法,其中从串联的两个电容之间的节点监测所述反馈电压,所述串联的两个电容与所述负载、所述变压器的二次侧并联。
9.一种经由变压器驱动灯负载的设备,包括:
用于监测所述变压器负载侧的反馈电压的装置;
用于确定所述反馈电压是否高于预设阈值的比较装置,并且
(1)如果高于,则使正常工作继续;以及
(2)如果不高于,则将所述设备提供的电流限制为安全电流ISAFE。
10.如权利要求9所述的设备,其中所述用于监测反馈电压的装置接收串联的两个电容之间的节点上的电压作为输入电压,所述串联的两个电容与所述负载、所述变压器的二次侧并联。
11.如权利要求9所述的设备,其中所述比较装置监测所述反馈电压,以确定该反馈电压是否在至少一个周期内低于所述预设阈值,如果低于则将所述提供的电流限制为ISAFE。
12.如权利要求9所述的设备,其中ISAFE是正常工作电流极限的均方根,或者是所述正常工作电流的平均整流值。
13.如权利要求9所述的设备,其中所述预设阈值在正常工作电压的25%到50%之间。
14.如权利要求9所述的设备,其中所述正常工作包括亮度电流命令,该亮度电流命令为电流的上限。
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US61864004P | 2004-10-13 | 2004-10-13 | |
US60/618,640 | 2004-10-13 |
Publications (2)
Publication Number | Publication Date |
---|---|
CN1784107A true CN1784107A (zh) | 2006-06-07 |
CN100591186C CN100591186C (zh) | 2010-02-17 |
Family
ID=36773750
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN200510113464A Expired - Fee Related CN100591186C (zh) | 2004-10-13 | 2005-10-13 | 在大面板应用中驱动放电灯的方法和保护设备 |
Country Status (4)
Country | Link |
---|---|
US (2) | US7265497B2 (zh) |
KR (1) | KR100713737B1 (zh) |
CN (1) | CN100591186C (zh) |
TW (1) | TWI318084B (zh) |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7554273B2 (en) * | 2006-09-05 | 2009-06-30 | O2Micro International Limited | Protection for external electrode fluorescent lamp system |
TWI318084B (en) * | 2004-10-13 | 2009-12-01 | Monolithic Power Systems Inc | Methods and protection schemes for driving discharge lamps in large panel applications |
TWI301352B (en) * | 2005-05-19 | 2008-09-21 | Mstar Semiconductor Inc | Full-bridge soft switching inverter and driving method thereof |
US7253569B2 (en) * | 2005-08-31 | 2007-08-07 | 02Micro International Limited | Open lamp detection in an EEFL backlight system |
KR101274590B1 (ko) * | 2006-06-30 | 2013-06-13 | 엘지디스플레이 주식회사 | 엘씨디 백라이트용 디지털 인버터의 엘씨씨 |
KR100876271B1 (ko) | 2007-05-29 | 2008-12-26 | 삼성에스디아이 주식회사 | 리튬 이차 전지 |
TWI375936B (en) * | 2007-05-31 | 2012-11-01 | Delta Electronics Inc | Light-source driving device and its signal transforming circuit and pulse generating circuit |
CN101453818B (zh) | 2007-11-29 | 2014-03-19 | 杭州茂力半导体技术有限公司 | 放电灯的电路保护和调节装置 |
US8076860B2 (en) * | 2008-11-06 | 2011-12-13 | Osram Sylvania Inc. | Power converter and power conversion method with reduced power consumption |
KR101642486B1 (ko) * | 2009-06-25 | 2016-08-01 | 페어차일드코리아반도체 주식회사 | 인버터 장치 및 구동 방법 |
US20110204964A1 (en) * | 2010-02-22 | 2011-08-25 | Jian Xu | Leakage current control circuit |
CN109362146B (zh) | 2018-10-09 | 2021-02-19 | 成都芯源系统有限公司 | 一种短路/开路保护的电路和方法 |
Family Cites Families (60)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4855888A (en) * | 1988-10-19 | 1989-08-08 | Unisys Corporation | Constant frequency resonant power converter with zero voltage switching |
JP2977604B2 (ja) * | 1990-11-22 | 1999-11-15 | 本田技研工業株式会社 | インバータ制御式エンジン発電機 |
US5528192A (en) | 1993-11-12 | 1996-06-18 | Linfinity Microelectronics, Inc. | Bi-mode circuit for driving an output load |
US5615093A (en) | 1994-08-05 | 1997-03-25 | Linfinity Microelectronics | Current synchronous zero voltage switching resonant topology |
US5619402A (en) | 1996-04-16 | 1997-04-08 | O2 Micro, Inc. | Higher-efficiency cold-cathode fluorescent lamp power supply |
US5757173A (en) | 1996-10-31 | 1998-05-26 | Linfinity Microelectronics, Inc. | Semi-soft switching and precedent switching in synchronous power supply controllers |
US5930121A (en) | 1997-03-14 | 1999-07-27 | Linfinity Microelectronics | Direct drive backlight system |
US5923129A (en) | 1997-03-14 | 1999-07-13 | Linfinity Microelectronics | Apparatus and method for starting a fluorescent lamp |
US6118415A (en) * | 1998-04-10 | 2000-09-12 | Eldec Corporation | Resonant square wave fluorescent tube driver |
US5892336A (en) | 1998-05-26 | 1999-04-06 | O2Micro Int Ltd | Circuit for energizing cold-cathode fluorescent lamps |
US6104146A (en) | 1999-02-12 | 2000-08-15 | Micro International Limited | Balanced power supply circuit for multiple cold-cathode fluorescent lamps |
US6946806B1 (en) | 2000-06-22 | 2005-09-20 | Microsemi Corporation | Method and apparatus for controlling minimum brightness of a fluorescent lamp |
US6198234B1 (en) | 1999-06-09 | 2001-03-06 | Linfinity Microelectronics | Dimmable backlight system |
US6804129B2 (en) | 1999-07-22 | 2004-10-12 | 02 Micro International Limited | High-efficiency adaptive DC/AC converter |
US6259615B1 (en) | 1999-07-22 | 2001-07-10 | O2 Micro International Limited | High-efficiency adaptive DC/AC converter |
US6198245B1 (en) | 1999-09-20 | 2001-03-06 | O2 Micro International Ltd. | Look-ahead closed-loop thermal management |
CN1251558C (zh) | 2000-05-12 | 2006-04-12 | O2米克罗国际有限公司 | 用于灯具加热和减光控制的集成电路 |
US6307765B1 (en) | 2000-06-22 | 2001-10-23 | Linfinity Microelectronics | Method and apparatus for controlling minimum brightness of a fluorescent lamp |
US6459602B1 (en) | 2000-10-26 | 2002-10-01 | O2 Micro International Limited | DC-to-DC converter with improved transient response |
US6501234B2 (en) * | 2001-01-09 | 2002-12-31 | 02 Micro International Limited | Sequential burst mode activation circuit |
KR100402091B1 (ko) * | 2001-02-06 | 2003-10-17 | 주식회사 지엘디 | 압전형 트랜스포머를 이용한 백라이트 구동 회로 |
US6570344B2 (en) | 2001-05-07 | 2003-05-27 | O2Micro International Limited | Lamp grounding and leakage current detection system |
US6515881B2 (en) | 2001-06-04 | 2003-02-04 | O2Micro International Limited | Inverter operably controlled to reduce electromagnetic interference |
US6507173B1 (en) | 2001-06-22 | 2003-01-14 | 02 Micro International Limited | Single chip power management unit apparatus and method |
US6657274B2 (en) | 2001-10-11 | 2003-12-02 | Microsemi Corporation | Apparatus for controlling a high voltage circuit using a low voltage circuit |
US6559606B1 (en) | 2001-10-23 | 2003-05-06 | O2Micro International Limited | Lamp driving topology |
TW595263B (en) | 2002-04-12 | 2004-06-21 | O2Micro Inc | A circuit structure for driving cold cathode fluorescent lamp |
US6864669B1 (en) | 2002-05-02 | 2005-03-08 | O2Micro International Limited | Power supply block with simplified switch configuration |
US6856519B2 (en) | 2002-05-06 | 2005-02-15 | O2Micro International Limited | Inverter controller |
US6873322B2 (en) | 2002-06-07 | 2005-03-29 | 02Micro International Limited | Adaptive LCD power supply circuit |
US6876157B2 (en) * | 2002-06-18 | 2005-04-05 | Microsemi Corporation | Lamp inverter with pre-regulator |
US6756769B2 (en) | 2002-06-20 | 2004-06-29 | O2Micro International Limited | Enabling circuit for avoiding negative voltage transients |
CN1706089A (zh) | 2002-10-21 | 2005-12-07 | 先进电力技术公司 | 具有高输入功率因数和低谐波失真的交-直流电源转换器 |
US6979959B2 (en) * | 2002-12-13 | 2005-12-27 | Microsemi Corporation | Apparatus and method for striking a fluorescent lamp |
US6778415B2 (en) | 2003-01-22 | 2004-08-17 | O2Micro, Inc. | Controller electrical power circuit supplying energy to a display device |
US6888338B1 (en) | 2003-01-27 | 2005-05-03 | O2Micro International Limited | Portable computer and docking station having charging circuits with remote power sensing capabilities |
US7095392B2 (en) | 2003-02-07 | 2006-08-22 | 02Micro International Limited | Inverter controller with automatic brightness adjustment circuitry |
US7057611B2 (en) | 2003-03-25 | 2006-06-06 | 02Micro International Limited | Integrated power supply for an LCD panel |
US6870330B2 (en) * | 2003-03-26 | 2005-03-22 | Microsemi Corporation | Shorted lamp detection in backlight system |
US6936975B2 (en) | 2003-04-15 | 2005-08-30 | 02Micro International Limited | Power supply for an LCD panel |
US6897698B1 (en) | 2003-05-30 | 2005-05-24 | O2Micro International Limited | Phase shifting and PWM driving circuits and methods |
US7187139B2 (en) | 2003-09-09 | 2007-03-06 | Microsemi Corporation | Split phase inverters for CCFL backlight system |
US7183727B2 (en) | 2003-09-23 | 2007-02-27 | Microsemi Corporation | Optical and temperature feedbacks to control display brightness |
JP4658061B2 (ja) | 2003-10-06 | 2011-03-23 | マイクロセミ・コーポレーション | 複数のccfランプを動作させるための電流分配方法および装置 |
WO2005043592A2 (en) | 2003-10-21 | 2005-05-12 | Microsemi Corporation | Balancing transformers for lamps driven in parallel |
US7183724B2 (en) | 2003-12-16 | 2007-02-27 | Microsemi Corporation | Inverter with two switching stages for driving lamp |
US8040341B2 (en) | 2004-01-09 | 2011-10-18 | O2Micro Inc | Brightness control system |
US7304866B2 (en) | 2004-02-10 | 2007-12-04 | O2Micro International Limited | System and method for power converter switch control |
US7394209B2 (en) | 2004-02-11 | 2008-07-01 | 02 Micro International Limited | Liquid crystal display system with lamp feedback |
US7112929B2 (en) | 2004-04-01 | 2006-09-26 | Microsemi Corporation | Full-bridge and half-bridge compatible driver timing schedule for direct drive backlight system |
US7250731B2 (en) | 2004-04-07 | 2007-07-31 | Microsemi Corporation | Primary side current balancing scheme for multiple CCF lamp operation |
US7126289B2 (en) | 2004-08-20 | 2006-10-24 | O2 Micro Inc | Protection for external electrode fluorescent lamp system |
US7161309B2 (en) | 2004-09-03 | 2007-01-09 | Microsemi Corporation | Protecting a cold cathode fluorescent lamp from a large transient current when voltage supply transitions from a low to a high voltage |
TWI318084B (en) * | 2004-10-13 | 2009-12-01 | Monolithic Power Systems Inc | Methods and protection schemes for driving discharge lamps in large panel applications |
US7061183B1 (en) | 2005-03-31 | 2006-06-13 | Microsemi Corporation | Zigzag topology for balancing current among paralleled gas discharge lamps |
US7173382B2 (en) | 2005-03-31 | 2007-02-06 | Microsemi Corporation | Nested balancing topology for balancing current among multiple lamps |
US7764021B2 (en) | 2005-04-14 | 2010-07-27 | O2Micro International Limited | Integrated circuit capable of enhanced lamp ignition |
US7911463B2 (en) | 2005-08-31 | 2011-03-22 | O2Micro International Limited | Power supply topologies for inverter operations and power factor correction operations |
US7253569B2 (en) | 2005-08-31 | 2007-08-07 | 02Micro International Limited | Open lamp detection in an EEFL backlight system |
US7372213B2 (en) | 2005-10-19 | 2008-05-13 | O2Micro International Limited | Lamp current balancing topologies |
-
2005
- 2005-10-12 TW TW094135598A patent/TWI318084B/zh not_active IP Right Cessation
- 2005-10-13 KR KR1020050096433A patent/KR100713737B1/ko not_active IP Right Cessation
- 2005-10-13 US US11/250,161 patent/US7265497B2/en not_active Expired - Fee Related
- 2005-10-13 CN CN200510113464A patent/CN100591186C/zh not_active Expired - Fee Related
-
2007
- 2007-08-21 US US11/842,867 patent/US7579787B2/en active Active
Also Published As
Publication number | Publication date |
---|---|
US7579787B2 (en) | 2009-08-25 |
US7265497B2 (en) | 2007-09-04 |
KR20060053245A (ko) | 2006-05-19 |
TWI318084B (en) | 2009-12-01 |
KR100713737B1 (ko) | 2007-05-02 |
US20060076900A1 (en) | 2006-04-13 |
TW200612782A (en) | 2006-04-16 |
CN100591186C (zh) | 2010-02-17 |
US20070285033A1 (en) | 2007-12-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN100591186C (zh) | 在大面板应用中驱动放电灯的方法和保护设备 | |
CN100342755C (zh) | 用于lcd屏的电源 | |
KR100902470B1 (ko) | 혼합 모드 직류/교류 변환기를 구비히는 장치 | |
US20060244395A1 (en) | Electronic ballast having missing lamp detection | |
CN1766715A (zh) | 灯单元的驱动装置和驱动方法及使用其的液晶显示装置 | |
CN101583229A (zh) | 多放电灯并联驱动电路及驱动方法 | |
CN101060744A (zh) | 放电灯系统中短路保护和过流保护的方法和电路 | |
KR20060052338A (ko) | 방전램프 제어장치 | |
CN201349354Y (zh) | 结合模拟及数字调光的背光源驱动装置 | |
CN1905774A (zh) | 放电灯照明设备 | |
CN1893754A (zh) | 操作至少一个电灯和至少一个led的电路装置和方法 | |
CN101868105B (zh) | 一种电子镇流器及其过压保护方法 | |
CN101064093A (zh) | 电压侦测电路及使用其的放电灯驱动装置 | |
US7579789B2 (en) | Device for driving light sources | |
CN1883238A (zh) | 检测电弧管外异常放电的放电灯镇流器 | |
CN1993009A (zh) | 检测灯开路状态的方法和电路 | |
US6930454B2 (en) | Method for operating at least one low-pressure discharge lamp and operating device for at least one low-pressure discharge lamp | |
CN1738508A (zh) | 用于驱动浮点配置的放电灯的方法和装置 | |
CN100516895C (zh) | 放电灯驱动装置及其应用的电压侦测电路 | |
CN2862572Y (zh) | 微波炉电源电压监测电路 | |
CN101145320A (zh) | 多灯管驱动电路、平面光源及显示装置 | |
CN200983711Y (zh) | 放电灯驱动装置及使用其的电子设备 | |
CN2696270Y (zh) | 一种新型高强度气体放电灯工频点灯电子镇流器 | |
CN1856201A (zh) | 驱动放电灯的高频电源装置及其频率设置方法 | |
KR200297681Y1 (ko) | 냉음극선관 구동장치 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
C10 | Entry into substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
C14 | Grant of patent or utility model | ||
GR01 | Patent grant | ||
C17 | Cessation of patent right | ||
CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20100217 Termination date: 20131013 |